Lamp Limiter Short Diagnosis
Interpret bright, dim, dead or pulsing lamp-limiter behavior before full-power testing.
Open tool →Browse Welder Repair Data
Use this database like a repair map: begin with the symptom, then move toward model, board, circuit, chip, workflow and tool pages.
Fault Symptoms
- Input short / lamp limiter bright ZX7
- IGBT / MOSFET keeps blowing Power stage
- Powers on but no output Inverter
- Auxiliary power supply no 24V Rails
- Control board shutdown / no PWM PWM
- ZX7 no open-circuit voltage OCV
- Stick spark but no arc A5 / driver
- ZX7 current cannot be adjusted Feedback
- TIG no high-frequency start HF
- MIG wire feed not working Wire feed
- Plasma cutter no pilot arc Pilot arc
Repair Workflows
- ZX7-250 complete H7B repair sequence Sample path
- ZX7 series common fault table Fault table
- Welding machine repair methodology Method
- MIG / MAG common fault routing MIG
- CO2 / MIG 6-wire feeder table Feeder
- LGK plasma common fault table Plasma
- MZ / ZD5 thyristor debugging checklist SAW
- Digital arc power source fault routing Digital
Machine Families
Board / Circuit References
- ZX7-250 driver and control power board Board
- ZX7-250 gate-drive transformer checks Gate drive
- ZX7-250 control power rails Rails
- TIG HF start 40V / 4s cutoff TIG
- MIG wire-feed / voltage control MIG
- MZ / ZD5 phase-shift trigger SCR
- Digital arc feedback control Digital
- IGBT / MOSFET induction power stage Industrial
Chips / Power Devices
Repair Cases / Tools
Symptom → Measurement → Workflow → Tool → Board Reference
This is the practical repair path WelderData is built around. It is strongest for ZX7 / inverter IGBT repair, and also extends into TIG, MIG, plasma and MZ / SAW troubleshooting.
1. Start with the fault symptom
No output, lamp limiter bright, IGBT keeps blowing, TIG no HF, MIG no wire feed, plasma no pilot arc.
2. Collect measurement evidence
Use DC bus, auxiliary rails, diode-mode checks, gate-drive branch comparison, shunt current and protection states before choosing a repair path.
3. Follow a repair workflow
Use complete paths when a fault spans power stage, control board, feedback, tools and staged power-up checks.
4. Use checklist tools
Rule-based tools help organize lamp-limiter behavior, IGBT replacement checks, rail readings and real current tests.
5. Open board-level references
Move into driver boards, auxiliary supplies, PWM control, wire-feeder boards, HF start boards and SCR trigger circuits.
Interactive Repair Tools
These are rule-based checklist helpers. They do not replace measurement, but they help organize evidence before board-level repair.
IGBT Replacement Precheck
Build a checklist before installing replacement IGBTs, MOSFETs or H7B power devices.
Open tool →Auxiliary Power Rail Checker
Enter measured +25V, -25V, +15V, -15V and +5V rails and get likely next checks.
Open tool →Current Display vs Shunt Check
Compare panel current display with external shunt or current-meter evidence.
Open tool →Core Repair Workflows
Use these when a problem is broader than one component and needs a full repair path.
ZX7-250 complete H7B repair sequence
Sample path from lamp-limiter short evidence to power-device checks, driver branch comparison, current validation and staged power-up.
Symptom → lamp limiter → DC bus / IGBT → driver branch → rails / pulse → shunt current → staged validation
ZX7 series common fault table
Symptom routing for ZX7-315 / 400 / 500 / 630 power, protection, TIG and output faults.
Power input → protection lamp → OCV / output → control board → feedback / calibration → model-specific route
General welder fault routing
Cross-platform routing for SMAW, TIG, MIG and plasma symptoms before replacing boards.
Trigger / command → gas / wire / HF / pilot arc → output enable → feedback → process-specific fault route
MZ / SAW thyristor debugging checklist
Sequence for control supply, synchronization, sawtooth ramp, SCR gate pulse, feedback and power-source interface checks.
Control power → sync → sawtooth → phase shift → gate pulse → feedback → output evidence
Major Repair Categories
Use these categories to browse machine families without losing the symptom-first repair path.
ZX7 / Inverter Stick
Portable MOSFET and IGBT welders, ZX7 series, input shorts, no output, driver and auxiliary-supply faults.
TIG / AC-DC TIG
HF start, gas timing, torch switch, 24V / 20V / 15V rails, AC square-wave and pulse TIG control.
MIG / MAG / CO2
Wire-feed, gas valve, voltage control, crater-fill, burn-back, feeder interface and pulse MIG routing.
Plasma Cutters
Air pressure, torch switch, HF ignition, pilot arc, arc transfer and common LGK / KLG fault routing.
MZ / Submerged Arc
Travel carriage, wire-feed control, arc-voltage feedback, SCR trigger circuits and SAW power-source interfaces.
Digital / Industrial Power
Digital arc power sources, MCU control, feedback mismatch and related IGBT / MOSFET industrial inverter supplies.
What WelderData Records
WelderData pages are written as technical repair records, not generic welding tutorials.
Diagnostic data
Fault symptom, likely section, first checks, stop conditions, normal readings, abnormal readings and next route.
Board-level references
Board role, connector function, auxiliary supply, drive circuit, feedback loop, shutdown path and output stage.
Repair-case data
Symptom, measurement, abnormal value, failed component, replacement action, staged restart and final validation.
Simplified technical diagrams
WelderData functional maps show the repair logic of a circuit without publishing raw source drawings.